The main purpose of this project is to assess the potential relationship between Irritable Bowel syndrome (IBS), psychiatric disorders, victimization/trauma (including physical and/or sexual abuse) and health care-seeking behavior in patients and nonpatients with IBS in community- derived samples. IBS is a common and sometimes debilitating functional gastrointestinal disorder which affects between 8-17 percent of the U.S. population (22-37 million individuals). The cost in the U.S. alone is estimated at one billion dollars annually. Only about half of the individuals in the U.S. who meet criteria for IBS have visited a physician for their symptoms. The extant literature indicates that a substantial percentage of the treatment-seeking IBS patients have psychiatric diagnoses (predominantly anxiety and mood disorders). It has been proposed that one of the factors mediating health care seeking is psychological distress/psychiatric illness. The limited literature indicates that individuals with IBS who do seek treatment exhibit more psychological distress, abnormal personality profiles and illness behavior than IBS sufferers who do seek treatment. Additionally, recent studies indicate that treatment-seeking IBS patients have a higher-than-expected prevalence of physical and/or sexual abuse history. Since victimization is associated with higher levels of health care utilization, victimization history has been proposed as a second variable mediating treatment-seeking in IBS patients. This project will be the first to utilize state-of-the- art instruments to assess the association of psychiatric disorders, victimization, health care utilization and pain/disability measures in a U.S. population-derived survey of IBS patients, IBS nonpatients, and a healthy comparison group. Interactions between variables such as IBS treatment-seeking history and victimization history will be examined for association with other (non-IBS) medical utilization, psychiatric disorder profile, psychosocial impairment and IBS severity and pain. Finally, variables demonstrated to be associated with health care utilization can be identified and targeted for intervention in future services research studies.